Offset printing machine



Juxie 23, 1931.

F. FISCHER OFFSET PRINTING MACHINE Filed March 21. 1928 2 Sheets-Sheet l /n venzor E Asa/76,,

' June 23, 1931. -F. FISCHER I O FSET PRINTING MACHINE Filed March 21. 1928 2 Sheets-Sheet v2 Patented June 23, 1931 STATES FERDINAND FISCHER, OF BERLIN, GERMANY OFFSET PRINTING MACHINE Application filed March 21, 1928, Serial No. 263,343, and in Germany April 14, 1927.

This invention relates to inking mechanism for offset printing machines.

The simplification of the elements in offset printing machines particularly for oflice use has led to the number of rollers in the inking mechanism being reduced. It is possible, with one wet roller and one inking foller, to satisfy the requirements of oflice printing. If the number of the intermediate rollers in the ink- 'ng mechanism is reduced a small number of parts are obtained in contrast to the number of rollers employed in larger machines.

According to the present invention the bringing into and out of operation of the small number of inking rollers used for office machines is effected in a novel and particularly suitable manner. In this case it is essential to combine positively the movement for bringing the rollers into and out of operation with an approaching and separating movement of all rollers.

Offset printing machines are already known in which the inking rollers are mounted in a movable frame and the Wiping or wet 2 rollers in another frame. In this case the movement of these frames serves only for disengaging and engaging the inking and wetting device but not for separating and approaching the individual rollers of the inking apparatus, and for the purpose of ensuring the correct combined action of both devices relatively complicated interlocks are required which the present invention renders unnecessar (In the other hand an inking mechanism for ordinary printing machines is already known in which a number of the rollers of the inking mechanism are mounted in a movable frame, the movement of which permits the engagement and disengagement of the inking mechanism. In this known arrangement two movable frames of bearing carriages with a relatively complicated mechanism using crosswise directed slots are provided. In this construction however only a simple engagement and disengagement is possible and not a suspension of contact of all rollers inter se.

As compared with this arrangement the present invention provides a much simpler construction and a greater variety of posirollers 8 and 9, which durin tions owing to the fact that some of the inking mechanism rollers are mounted stationary on the machine frame and that only a single movable frame is provided by the movement of which the relative contact of all inking rollers can be suspended.

The invention is illustrated by way of example on the accompanying drawings in which:

Figs. 1, 2 and 3 illustrate diagrammatically one embodiment of the invention.

Figs. 4 and 5 illustrate diagrammatically a further embodiment of the invention.

Figs. 6 and 7 illustrate diagrammatically a further embodiment of the invention.

Figs. 8, 9, 10 and 11 illustrate four different positions of the inking mechanism and Fig. 12 illustrates a plan View of a detail.

The forme cylinder 1 is mounted on the machine frame. .The five rollers 2, 3, 4, 5, 6 of the inking mechanism are, as in itself known, divided into two separate groups. One group comprising the intermediate inking cylinders 3 and 5 is mounted in a fixed position relative to the forme cylinder in the machine frame and the second group comprising-the inking rollers 2, 4, 6 is mounted on a movable frame 7 by means of which all desired conditions of contact necessary for handling the machine can be produced.

In Fig. 1 the inking cylinders 3 and 5 and the inking rollers 2, 4 and 6 are in contact inter se whilst two of the inking rollers 2 and 4 are in contact with the forme cylinder 1 In Fig. 2 the inking mechanism is out of contact with the forme cylinder 1 but the inking cylinders and inking rollers are in contact with one another for distributing and reworking the ink on these rollers. In Fig. 3 the inking rollers are brought out of contact with the inking cylinders.

As shown in Fig. 4, the frame 7 in addition to theinking rollers 2, 4, 6 also carries wiper progressive movement of the frame in the dlrection of the arrows can be brought into and out of contact with the forme cylinder 1.

In the inking mechanism shown in Fig. 6 the frame 7 is pivotally mounted at 10 and moves on this pivot instead of moving in parallel guides. A single inking roller 2 serves as the distributing roller. When the frame 7 is swung in the direction of the arrows the three working positions above described are also passed through as the inking cylinder 3 which is mounted in the machine frame remains stationary.

Fig. 7 shows the same pivotally mounted frame with the addition of a wiper roller 12 Lnounted in a slot 11. This arrangement enables the frame 7 to be brought into four positions which are adapted to the inking processes necessary in offset printing. These four positions are shown in Figs. 8, 9, 10, 11.

Fig. 8 shows the main working position in which the wiper roller 12 and also the ink distributing roller 2 are in contact with the forme cylinder 1. In Fig. 9 the frame 7 has been slightly moved on its pivot so that the distributing roller 2 is raised off the forme cylinder 1 whilst the wiper roller 12 is still imposed on the forme cylinder as the slot 11 in which it is mounted extends to a suitable depth in theframe 7. In the said slot 11 the usual cleaning roller 13 is mounted.

In Fig. the wiper roller 12 is also swung away from contact with the forme cylinder 1, but between the inking roller 2 the inking cylinder 3 and inking roller 4 friction is still maintained. In Fig. 11 the frame 7 is swung away to its extreme position so that the inking rollers 2 and 4 are out of contact with the inking cylinder 3.

These four positions can be obtained by engaging the hand lever 14 in one or the other of four recesses 15, 16, 17, 18 in the frame 7. The lever 14 may be considered as having two pivot points 21 and 22. The lower portion 19 of the lever has a projecting pin 20 which engages an orifice 24 in a plate spring 23 one end of which is pivoted at 22. A further frame plate 7 is arranged opposite the first-mentioned plate on the other side of the machine. The crank arm 19 with the pin 20 is also connected by means of a spindle 21 with a crank arm on the other side of the machine. The inking mechanism has thus two pairs of connections with the machine one comprising the two frame plates 7 and the other the two plate springs 23 pivoted at two analogous points 22 and having orifices 24 which according to Fig. 12 are slipped over the pins 20 on the two arms 19.

On referring to Fig. 12 it will be seen that the whole inking mechanism can be removed from the machine and changed when desired by disengaging the orifices'24 from the two pins 20 and by removing the two frame plates 7 which have open bearlngs on pivots 10.

From the above it will be seen that in one position of rest i. e. when the lever 14 engages the recess 15, the wiper roller 12 and the inking roller are in contact with the forme cylinder.

When the lever 14 engages the recess 16 the inking roller 2 is out of contact with the forme cylinder whilst the wiper roller 12 owing to its slotted bearing is in engagement with the said cylinder.

When the lever 14 engages the recess 17 the roller 12 is out of contact with the cylinder 1 and the inking rollers 2 and 4 are in contact with the inking cylinder 3. ii

In the remaining position i. e. when lever 14 engages recess 18 all the rollers are out of contact with one another.

.The number of the inking and wiper rollers may be varied as desired.

From the drawings it can be seen that by the advancing movement of the frame or slide, the rollers of the one group are clamped in correspondingly proportioned spaces between the rollers of the other group and are removed from such spaces by the returning movement of such frame or slide and that the elasticity of the rollers themselves is made use of, for maintaining the clamping condition in engaging or disengaging the inking rollers.

What I claim is Inking mechanism for offset printing machines comprising a movable frame, inking rollers on the frame, an inking cylinder on the machine, and means whereby said frame may be adjusted to and held in different positions so that the inking rollers can be brought in to and out of contact with the usual form cylinder and the inking cylinder and into a position in which they'contact only the inking cylinder.

In testimony whereof I afiix my signature.

FERDINAND FISCHER. 

